According to the International Telecommunication Union (ITU), mobile broadband subscriptions worldwide will reach 2.3 billion by the end of 2014. These subscribers no doubt contribute to the over six billion hours of YouTube videos that are watched in a single month. That’s nearly an hour for each person on Earth, according to YouTube.

Ask anyone, and you know that most people dislike when their calls drop, or when the dreaded ‘loading’ icon disrupts their live stream of the playoff game. Carriers realize this, and know that network speed and reliability are driving forces behind consumer satisfaction in today’s connected world. With the exabytes of data sent across today’s networks, however, speed and reliability can be difficult to maintain consistently.

What’s less commonly known is the role that network timing and synchronization play in this whole equation. 4G LTE networks, for example, rely on highly accurate timing and synchronization for smooth cell-to-cell transfers of the mass of voice, video and mobile data.

4G LTE, LTE-A – What’s The Difference?

But first, some background about what 4G LTE really means. LTE is a broad umbrella encompassing three different network types:

- Frequency Division Duplexed LTE, or FDD LTE, uses paired spectrum – one for upstream traffic and the other for downstream. FDD LTE was used in some of the early LTE deployments and is still deployed today;

- Time-Division Duplexed LTE, or TDD LTE (also sometimes called TD-LTE), is more spectrally efficient. Unlike FDD LTE, TDD LTE requires only a single spectrum band for both upstream and downstream traffic, flexibly allocating bandwidth by timeslot, and generating significant cost savings for carriers in spectrum licensing fees; and

- LTE-Advanced, or LTE-A, is an upgrade to either of the two types outlined above, delivering greater bandwidth by pooling multiple frequency bands and allowing simultaneous data transmission from multiple base stations to a single handset.

These different ‘flavors’ of LTE need different types of synchronization, and wireless networks use what’s called frequency synchronization and time-of-day synchronization. FDD LTE only needs frequency synchronization. TDD LTE and LTE-A, on the other hand, require both. And therein lies the challenge.

Historically, wireless networks have used global positioning satellite (GPS) as the main timing source, since it can provide both frequency and time-of-day synchronization. But carriers now recognize its drawbacks, especially as networks rely more on small cells (femtocells and picocells) for increased coverage and capacity. Often, small cells installed at street level or indoors lack a direct line of sight to GPS satellites. Even if that weren’t the case, adding GPS technology to these units would make them too expensive to deploy on a mass scale. Add to that the growing concerns about GPS spoofing and jamming, plus the unwillingness of countries outside the U.S. to depend exclusively on the U.S. government-run GPS satellite system for their wireless networks, and clearly carriers need alternatives.

Fortunately, there is an alternative: IEEE 1588 Precision Time Protocol (1588 or PTP). Not only can it deliver the frequency and time-of-day synchronization needed in TDD LTE and LTE-A networks, but it’s more cost-effective than GPS as well. Especially as carriers rely more on heterogeneous networks, or HetNets, using 1588 as a GPS-alternative for network timing becomes more critical. By definition, HetNets are comprised of both fiber and microwave equipment, including the more widespread small cells mentioned above. Compounding this is the fact that most carriers use network equipment from several vendors, which may or may not offer 1588 support.

True, most wireless customers ultimately won’t care how they get their services, just that they work when and where they’re needed. But from a network infrastructure perspective, IEEE 1588 is here to stay. Carriers need to look for it and plan accordingly as they continue their network rollouts to support next-gen advanced wireless services.

Wednesday, Apr 23, 2014

PODCAST: Over 1.4 zettabytes. That’s Cisco’s projection for annual global IP traffic by the end of 2017. This translates to 120.6 exabytes per month, a more than 4x increase in the past five years, and an expected 3x increase over the next five years. If you think that this doesn’t impact you, you should take a closer look. You, your company, even your household are all contributors to this explosive traffic growth. How, you ask? Largely through public and private sector demand for mobile and cloud networking services, two of the most significant trends impacting the communications industry today.

Wednesday, May 14, 2014

BLOGPOST: Ask anyone, and you know that most people dislike when their calls drop, or when the dreaded ‘loading’ icon disrupts their live stream of the playoff game. Carriers realize this, and know that network speed and reliability are driving forces behind consumer satisfaction in today’s connected world. With the exabytes of data sent across today’s networks, however, speed and reliability can be difficult to maintain consistently. What’s less commonly known is the role that network timing and synchronization play in this whole equation. 4G LTE networks, for example, rely on highly accurate timing and synchronization for smooth cell-to-cell transfers of the mass of voice, video and mobile data.

Tuesday, Jun 3, 2014

BLOGPOST: $19 trillion. That’s the Internet of Things (IoT) market size as recently estimated by Cisco CEO John Chambers. According to Morgan Stanley forecasts, some 75 billion devices could be connected to the IoT by 2020, or 9.4 devices for each one of the eight billion people on earth. While much of the hype is on the consumer side and still coming to fruition, the industrial IoT is an entirely different animal and very real today. There are multiple industrial IoT applications where the embedded machine-to-machine (M2M) networking between ‘smart objects’ already exists. This includes a range of commercial, industrial and government applications, ranging from video surveillance and security, smart energy, intelligent transportation, digital signage, manufacturing automation and even automotive connectivity, to name a few. And these applications have far more exacting requirements than consumer-based IoT, the key ones of which we’ll address.

Tuesday, Jul 1, 2014

BLOGPOST: According to Google Developer Advocate, Don Dodge, the Internet of Things (IoT) requires a ‘brand new network.’ He made some great points at the recent MIT Technology Review Digital Summit, but the linchpin of what he’s really talking about here is small cells. That is, the femto-, pico- and microcells that carriers use to fill in the coverage and capacity gaps in their networks. These are the same small cells that have become so commonplace that AT&T actually has a whole commercial campaign essentially explaining small cells and how they’re using them to improve their network.

Tuesday, Oct 7, 2014

BLOGPOST: A recent WIRED article claimed that millennials don’t care about mobile security. But like it or not, the fact is that that security in mobile networks is a growing concern, and clearly an issue that’s not going away anytime soon. As my colleague, Martin Nuss, pointed out in a panel discussion at CTIA Super Mobility Week last month, the explosion in 4G networks driven by small cell deployment, coupled with the tremendous growth in BYOD, has created a global IT security threat that needs urgent attention.

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